An active image information system for biomedical image databases is developed based upon the concept of smart images. A smart image is an image with an associated knowledge structure, consisting of protocols, hot spots, active indexes and attributes. This active image information system supports the objectives of timely delivery and easy accessibility of biomedical image data. The experimental prototype of the smart image system is developed by researchers at the Department of Computer Science and tested at the Cardiology Division of the University of Pittsburgh. The decision protocols are implemented using the smart image system, so that a physician or a cardiologist can retrieve and display images from different sources, and conduct the normal diagnostic procedures. The automation of this medical image information gathering and archiving process greatly benefits the cardiologists to relieve them from the tedious repeated work and to enable them to concentrate on patient treatment. The active image information system and medical image databases will also provide a testbed for advanced research in image databases, with potential applications to process control, power plant outage management and other areas.